Recently one of our customers emailed us asking about the “whirring” sound coming from his laptop computer. He recognized the sound as the internal fan as it turns on to cool down the unit. He wanted to know what generates the heat and if the laptop might be overheating. Here was our response:

Typically the hard drive will not cause overheating, although it does have a motor which generates some heat. The normal operation of a laptop computer causes heat which triggers the fan to run frequently (if not constantly) under normal use. Most of the heat is generated by the resistance to the electricity flowing through circuits inside the computer. Because laptops are designed to be small and portable, all these chips and circuits are in close proximity and have tight air flow channels. Cooling is tougher than with desktop computers.

The most common high sources of heat during normal operation are:

• CPU
• RAM (memory)
• Video chip

These computer components will generate more heat the harder they work, i.e. the video card will generate more heat while you are watching a video or generating graphics, and the CPU will generate more heat when it is performing more calculations. Consequently the fan runs faster when the components generate more heat. Other chips on the main board of the computer also generate heat, but typically to a lesser degree.  All laptop fans are variable speed – the speed changes to keep the internal temperature below a certain limit”

The most common reasons a fan will run more, or run louder, are:

• Dust coating or plugging the insides of the laptop thus reducing heat transfer efficiency.
• One, or more, of the laptop vents which are located on the bottom and sides of the laptop are obstructed. This obstruction reduces the air flow through the laptop internals. Generally, laptop computers should not be placed on beds, laps, or pillows because the bottom vents will be blocked.
• The fan bearings are going bad and the fan is running roughly.
• The fan blades are unbalanced which is typically VERY noisy
• The thermal compound (goop) between the heatsink and the heat source is breaking down and needs to be replaced.

Cantrell’s Computer Sales & Service, Inc. make the complex world of computers and IT networks easier for our customers. Please contact us for more information! Wade Cantrell is the CEO of Cantrell’s Computer Sales & Service, Inc. which is a value-added reseller and computer service business  located in Concord, California.  We stock and source highly reliable computer equipment and parts.  We have been serving Central Contra Costa County customers (and beyond) since 1998. For further advice on computers and computer-based solutions, business IT network issues, virus and malware removal, data recovery, and computer repair, call any member of the award-winning staff at (925)827-1200 to set an appointment.